Function idamax_

numpy/linalg/lapack_lite/f2c_blas.c:10739–10815

} /* icamax_ */

integer idamax_(integer *n, doublereal *dx, integer *incx)
{
    /* System generated locals */
    integer ret_val, i__1;
    doublereal d__1;

    /* Local variables */
    static integer i__, ix;
    static doublereal dmax__;


/*
    Purpose
    =======

       IDAMAX finds the index of element having max. absolute value.

    Further Details
    ===============

       jack dongarra, linpack, 3/11/78.
       modified 3/93 to return if incx .le. 0.
       modified 12/3/93, array(1) declarations changed to array(*)

    =====================================================================
*/

    /* Parameter adjustments */
    --dx;

    /* Function Body */
    ret_val = 0;
    if (*n < 1 || *incx <= 0) {
	return ret_val;
    }
    ret_val = 1;
    if (*n == 1) {
	return ret_val;
    }
    if (*incx == 1) {
	goto L20;
    }

/*        code for increment not equal to 1 */

    ix = 1;
    dmax__ = abs(dx[1]);
    ix += *incx;
    i__1 = *n;
    for (i__ = 2; i__ <= i__1; ++i__) {
	if ((d__1 = dx[ix], abs(d__1)) <= dmax__) {
	    goto L5;
	}
	ret_val = i__;
	dmax__ = (d__1 = dx[ix], abs(d__1));
L5:
	ix += *incx;
/* L10: */